Fabric dyeing method and apparatus



April 30, 1940. c. R. JOHNSON I FABRIC DYEING METHOD AND APPARATUS Filed Aug. 9, 1937 2 Sheets-Sheet 1 INVENTOR C\- wAzCR KQ\\ Se x mgwgg ATTORNEY April 30, 1940. c. R. JOHNSON FABRIC DYEING METHOD AND APPARATUS Filed Aug. 9, 1937 2 Sheets-Sheet 2 lrl INVENTOR I ck nrbtS k-nku g ATTORNEY Patented Apr. 30, 1940 FABRIC DYEING IMETHOD AND APPARATUS Charles B. Johnson, Springfield, Mm, assignor ,to Bigelow-Sanford Carpet 00. Inc., Thompsonville, Conn, av corporation of Massach usettl Application August a, 1937, Serial No. 158,068

BOlaims.

This invention relates to the dyeing of pile fabrics, such as floor coverings, and particularly to a novel method and apparatus for the purpose which produce a superior product in a more effective manner than heretofore.

The dyeing of pile fabrics by immersion of the fabric in a dye bath is a difllcult art because of the peculiar manner in which the yarns, and particularly the pile tufts, take the dye from the bath. As the fabric is fed through the bath. the pile yarns have a tendency to absorb, selectively, certain of the components of the bath more than others, leaving the bath excessively rich in ingredients not as readily absorbed, and thereby changing the composition of the bath in which successive portions of the fabric are immersed. A different coloring of the fabric from end to end results which is obviously undesirable.

The primary object of the present invention is to obviate such selective absorption and, for that purpose, to employ, in place of the usual dye bath of substantial size, a bath consisting of a small quantity of dye liquor which is continuously replenished from a supply source with dye liquor of uniform composition and thus prevented from changing its composition as the fabric passes through it. The effectiveness of this .method of dyeing is enhanced by passing the fabric through the bath at a speed to remove the fabric from the dye bath before material exhaustion of the dye from the bath ontothe pile takes place.

I have been able to efiect uniform and thorough penetration of the dye liquor into the pile tufts while the fabric is thus rapidly passing through the small dye bath, by opening or spreading the tufts very substantially while in the bath, and one of the objects of my invention is to provide a device for so opening the pile. As will appear, my preferred method is"to bend the fabric back sharply on itself as it passes through the bath, thus causing the individual pile tufts on the outside of the bend to flare or spread apart and thus afford access for the dye bath.

These and further objects and advantages of my invention will appear from a more detailed description thereof taken in connection with the accompanying drawings in which:

Fig. 1 is a diagrammatic showing of my process and the equipment used therewith;

Fig. 2 is a perspective of the dye bath and carpet'being dyed therein;

Fig. 3\is a section on the line 3-3 of Fig. 2 showing in detail the dyeingoperation.

Referring now to l, which shows diagramsteamer the carpet matically the several steps in my novel process, 2

is a mixing tank containing a supply of dye liquor. Within this tank is a heating coil 4 used to maintain the dye liquor at the proper temperature, to be described, the said coils being connected by automatic control 6 to'a steam supply to maintaina constant temperature of the dye liquor. The tank is also preferably provided with an agitator of common type tokeep the dye mixed. Extending from the bottom of the mixing tank is an outlet pipe 8 which bends downwardly and terminates in a horizontally extending perforated pipe ill, see Figs. 1, 2 and 3. Immediately below the pipe I is a sloping apron l2 somewhat longer than the pipe Ill and this apron extends downwardly to a small tank It, the shape and size of which can readily be seen in Figs. 2 and 3.

In the preferred form of my invention, the tank I4 is in the neighborhood of one and one-half inches deep and one and one-half inches wide at the top, the length being sufficientto accommodate the width of the carpet with which it is to be used.

From the construction described thus far, it is apparent that dye liquor can flow from the mixing tank 2, through the outlet pipe 8 to the horizontal perforated pipe III, wherefrom it may be discharged evenly along the apron l2 to accumulate as at I! in the tank ll. A control valve I6 is provided in the pipe Q to regulate the rate of flow into the dyeing tank.

Carried by supports i'l (Fig. 2) and extending longitudinally of the tank It, is a wooden breaker bar l8 covered along its lower, V-shaped, edge by a sheath 20. This sheath may be of any suitable material but I have found that copper works satisfactorily in thatit oifersvlittle frictional resistance to the carpet being drawn thereabout.

It will be observed in Fig. 3 that the lower edge of breaker bar I8 is set sufliciently far down within trough I 4 so that the carpet, passing around it, will be completely immersed in the small bath of dye liquor. Adjustments (not shown) may be provided for raising or lowering the breaker bar a limited amount to regulate the immersion,

From a source of carpet supply 22, the carpet is drawn over suitable rolls 24, 26, 28 and 30, of which 26, 28 and 30 are tension rolls, from which it passes vertically downwardly, to be doubled back about the lower edge of breaker barl8, whence it is drawn upwardly to pass over rolls '32, 34 and 36 to enter a steamer 38. From the passes through a pair' of squeeze rolls 40, thence through a water rinse tank 42, to a second pair of squeeze rolls 44, and finally into a dryer 46, whence it emerges to be rolled up or otherwise stored as at 48. The foregoing is a summary of the operations involved in my dyeing method and the procedure will now be described more in detail.

Preferably, the carpet supplied at 22 is well scoured and thoroughly dried. By power which may be supplied by certain of the rolls over which it passes, such as rolls 40, 44 and 48, the carpet is drawn from the supply to the dye bath in tank M. In order that there may be uniformity in the speed of travel as the carpet is drawn through the dye bath, I have provided roll 28 with a friction brake and with spikes and I thus also obviate any tendency of the carpet to jump when seams pass by the tension rolls, which might cause non-uniformity in the dyeing.

The carpet has a backing material and a face of pile 52, which are plainly shown in Fig. 3. It is apparent that as the carpet is bent sharply around the lower edge 54 of the breaker bar with the backing 5|] adjacent the bar the pile will be completely opened as it passes through the dye liquor IS in tank l4. Because of this complete opening, the dye liquor l5 has ample opportunity to reach the pile throughout its entire depth so that uniformity of color of the pile from top to bottom is obtained. In addition, opening the pile in this manner allows the dye liquor easily to reach and penetrate the ground fabric, if desired, and as determined by the vertical adjustment of the breaker bar l8.

With my apparatus, the relation between the amount of dye maintained in the tank I4 and the rate at which the fabric is drawn through it may be such that the dye in the tank I4 is completely changed many times a minute, thus effectively eliminating selective absorption. Preferably, I employ a rate of feed for the carpet of twelve feet per minute and so regulate the quantity of dye liquor maintained in the tank l4 that it is completely changed approximately every one and three quarters seconds. Since approximately twenty ounces of dye liquor are required to dye a square foot of ordinary carpet, the quantity of dye which I preferably maintain in the tank I4 for a carpet feed rate of twelve feet per minute is about seven ounces of dye liquor per foot length of the tank and the same quantity of new dye liquor is therefore continually supplied to each foot length of tank approximately every one and three quarters seconds. These figures are merely illustrative, however, since good results may be obtained with considerable variation from the stated rates of fabric feed and dye bath change, and since rate of dye bath change for a given quantity bath varies not only with the speed at which the fabric is drawn through it but also with the absorptive characteristics of the particular fabric being dyed.

Since the dye liquor issuing from the tank 2 can be kept uniform in color by batch mixing and thorough agitation, and since it is taken up almost immediately by the fabric, it follows that each successive portion of fabric will be dyed with liquor which is uniform in color. Thus, uniformity in shade is obtained throughout the dyed fabric. The thorough opening of the pile as it passes over the lower edge of the breaker bar I 8 assures adequate penetration of the dye liquor into the pile and ground, although the fabric is in the dye bath a very short period of time.

Although my invention is not so to be limited, I rfer to use acid rather than chrome dyes as the former require a lesser immersion time. In using acid dyes the amount of acidity and the temperature should be controlled to produce optimum results. Thus if excessively acid, the dye has a tendency to take too quickly and produce non-uniform results, while if the dye is not sufiiciently acid, it may not take with sufficient rapidity for complete exhaustion of the dye from the liquor by the time the excess liquor is removed. The temperature of the dye bath also affects in like manner the rate at which the dye will take in the fabric. I have obtained good results by using a bath containing about three times as much formic acid by weight as coloring ingredients and with such acidity a dyeing temperature of around F. is satisfactory. To obtain that temperature in the dye bath the liquor in the storage tank should be maintained at a temperature of approximately 200 and I have found that an even temperature is maintained in the dyeing tank without heating means in addition to that in the storage tank.

The fresh dye introduced to the tank l4 should preferably not contact the pile prior to becoming mixed with the dye in the tank as streakiness might possibly result. To obviate any possibility of such engagement, a bafiie may be used in the tank l4, but I have found that the apron spillway I2 prevents such contact if at a proper angle, such as shown.

on leaving the dye bath the carpet proceeds to the steamer 38, where it enters at the bottom and passes upwardly and downwardly over a number of easily running rolls as shown. Steam is supplied to the steamer by means of the perforated steam pipe 56. The path of the carpet within the steamer is such that each portion. of the carpet is acted on for a proper time, such as ten minutes. This treatment serves to bring out the color and sets the dye in such a manner that crocking is minimized.

On leaving the steamer the carpet is drawn through a pair of squeeze rolls to eliminate excess liquid, following which it passes through the water rinse tank 42. This operation-washes away surplus dye and generally cleanses the carpet. From the water rinse the carpet passes through a second pair of squeeze rolls 44 which again eliminate a large part of the surplus water and from these rolls the carpet passes to the dryer 46 which should, of course, be sufiiciently extensive to dry thoroughly the fabric atthe rate of feed employed. Upon emerging from the dryer, the finished carpet is collected in any convenient manner, as for example, in the roll 48.

While I have illustrated and described a preferred form of my apparatus and method, I wish it to be understood that I do not intend to be limited thereby except as indicated in the appended claims.

I claim:

1. The method of dyeing pile fabrics which includes passing the fabric through a dye bath and simultaneously bending the fabric backwardly on itself, while in the bath, in an amount sufficient to expose the base of the pile to the dye.

2. The method of dyeing pile fabrics which includes passing the fabric through a dye bath containing at any instant an amount of dye insufficient to dye more than a portion of said pile fabric, continuously replenishing the dye bath as it is used and bending the fabric backwardly on itself while in the bath to expose the base of i the pile to the dye.

3. The method of dyeingpile fabrics which includes passing the fabric through a dye bath by immersion therein to a depth not substantially exceeding that required to submerge the pile and simultaneously bending the fabric backwardly on itself while in the bath to expose the base of the pile to the dye.

4. Apparatus for dyeing pile fabrics comprising a dye tank of small capacity, an acutely edged breaker bar extending across said dye tank adjacent the surface of the dye for bending the fabric sharply in the bath to open the pile, and means for supplying dye to the tank including a drip apron extending along one edge of said tank and extending away from said breaker bar to 0bviate direct contact of the incoming dye with fabric drawn about said bar.

5. The method of dyeing a pile fabric which consists in wetting the pile down to the backing fabric with dye liquor by opening the pile while passing the fabric through the dye liquor, re-

moving the fabric from the dye liquor before material exhaustion of the dye onto the pile takes place, retaining substantially all of'the wetting dye liquor in the pile after said removal, then steaming the fabric containing all such wetting dye liquor to set the dye in the pile, and drying the dyed fabric.

6. The method of dyeing a pile fabric which consists in passing the fabric through a dyebath of a concentration such that the quantity of liquor taken up by the pile when saturated with all the dye liquor which the fabric will hold contains sufficient igment to dye to the desired shade, opening he pile while in the bath to accelerate taking up of the liquor by the pile, removing the fabric from the bath as soon as it has become saturated with liquor and setting-the dye in the fabric While still saturated.

CHARLES R. JOHNSON. 

